Airplane running light lamp



April 1, 1941. w -g 2,237,072

AIRPLANE RUNNING LIGHT LAMP Y Filed April 29, 1939 v I.\'1 fl; Mzenv G.GE/NES Patented Apr. 1, 1941 UNITED STATES PATENT OFFICE AIRPLANERUNNING LIGHT LAMP WarrenG. Grimes, Urbana, Ohio Application April 29,1939, Serial No. 270,893

2 Claims.

This invention relates to an airplane running or position light lamp anda method of focusing the beam light thereof.

The further object of this invention is to provide a more eificientairplane running light of exinvention. The running light l includes ahousing base The housing base consists of 3.

tremely small size whereby the light will be much more effective thanthe minimum requirements and at the same time far smaller and hencecause loss aero dynamic resistance than the present conventional typesof running lights.

The further object of this invention is to provide a lamp for anairplane running light, which lamp is so specially shaped and has areflector formed thereon whereby the light beams will be cut off fromundesired directions and intensified in desired directions so as toprovide a light having a candle power far above the minimum requirementseven after the light has passed through the red or green colored window.

A still further object of this invention is to pro vide a running lightlamp which has its beam light from the filament pre-focused withrelation to a standard socket in which it is placed. Each lamp will inaccordance to this invention always throw thebeams of light of thedesired intensity in the same direction when placed in the same typesocket.

The further object of this invention is to provide a means ofpro-focusing the beam light in relation to the socket and then fixingone part of the base by securing means to the lamp which securing meanswill cooperate with the standard socket in the proper placement of thelamp in the socket and make improper placement impossible,

With the foregoing and other objects in view as will hereinafter becomeapparent, this invention comprises the combinations of construction andarrangement of parts hereinafter claimed, set forth, and illustrated inthe accompanying drawing, wherein:

Figure 1 is an exploded perspective view of the running light of thisinvention.

Figure 2 is a side elevational view, partly in section, of the runninglight.

Figure 3 is an elevational view partly in section of the improved lampof this invention.

Figure 4 is a sectional view on line 4-4 of Figure 3.

Figifre 5 is a side elevational view of the securing shell.

Figure 6 is an end elevation of Figure 5, and

Figure 7 is a perspective view of the securing collar or ring to bemounted on the lamp.

There is shown at Hi the running light of this counter-bored cylinder l2from which extends a bowl l4 terminating in a somewhat elliptical flangeIS. The flange I5 is provided with a circular recess I6 and a pluralityof slots to receive the base I8 and extending prongs I9 of alens-covering dome 20, of transparent, colored material (glass or glasssubstitute) usually colored either red or green according'to itslocation on the airplane in accordance with regulations. A dome-securingshield 2| has a spherical section 22 fitting snugly over a portion ofthe dome to hold it securely in position. The shield 2| is itself heldsecurely on the flange l5 by suitable machine screws placed thruopenings 23 in the shield and screwed into threaded apertures 24 and thebowl flange I5, a. depending flange 25 on shield 2| extending over theoutside of the bowl flange I5.

Suitably and immovably secured within the counterbored cylinder I2 isthe lamp-securing shell 26 having one endthreaded as at 21 to receive aknurled cap nut 28 thereover, which nut supports the spring 30 againstan insulation ring 3|. The insulation ring 3| has 'the bared end of aconductor 32 soldered therein to form a terminal 33; The conductor 32extends thru the center of the cap nut 28, 30 and the axial center ofthe coiled spring 30. The unthreaded end of the securing sleeve 26 hasan enlarged head 34 which is provided with three unequally spacedbayonet slots 35.

The lamp 36 of this invention includes a lamp base 31 forming onecontact and provided with a single contact 38 extending concentricallythereof, these contacts being connected to the filament 40 within thelamp 36 in the customary manner.

The lamp bulb 4| is not completely spherical in shape as is customary,but instead consists of one approximately spherical section 42 and asomewhat flattened section of a sphere of larger radius 43, the section43 having a radius much greater than the spherical section 42. Section43 and the lower or basal half 44 of spherical section 42 are silveredas at 45 so as to reflect all light striking the same thru theunsilvered or clear portion 46. Sections 42 and 43 are so chosen thatthe light is emitted from the lamp 42 only in the directions called forby existing standard aircraft requirements concerning running lights andmay be changed if and when the requirements are changed, the light inall other directions being cut of! and reflected so as to intensify thelight in the desired direction.

.dynamic resistance thereof.

The interior volume of the lamp bulb 4| which may be evacuated or filledwith inert gas is substantially equal to that of a conventional bulbment and having conventional reflectors placedoutside the conventionalspherical shaped lamp bulb.

The conventional running light emits 8 to foot candles of light, but theminimum requirements by the Bureau of Air Commerce Regulations may beraised to require a greater light intensity visible through the coloreddome. To comply with such regulations, it will be necessary to increasethe size of the conventional running light thus increasing the weightand the aero- The lamp of the present invention has been found by actualtest to emit more than 75 foot candles of light as viewed thruthecolored dome 20, and far from being larger in size than the regulationrunning light is in fact much smaller as it is substantially one quarterin over-all size in comparison to the conventional running light,therefore producing a much more intense light with less space andlessa'erodynamic resistance.

The lamp 36 of this invention is mounted in the socket shell 26 by meansof a securing collar 46 having an internal diameter slightly larger thanthe external diameter of the lamp base 31. This securing collar 46 isprovided with a plurality of bayonet prongs 41 spaced thereabout at thesame 7 angle as the bayonet slots 35 so that the lamp 4 lamp base 31.

shell 26, the ring 46 being in position in the bayonet slots 35 but asyet unconnected to the When the lamp has the desired beam light properlyfocused, the securing collar 46 and lamp base 31 are secured together bya suitable solder about the edges and in between the collar 46 and thelamp base 31, so that the lamp 36 is then in a position to emit its mostintense beam light in proper relation to the ring 46. As the resultthereof, when one lamp burns out and is replaced by another madeaccording to this same method it is certain that the new lamp willemit'its beam light in the same direction and same intensity as theoriginal lamp irrespective of any slight inaccuracies between theposition of the filament 40 and the silvered reflecting surface 45.

The novel features and the operation of this device will be apparentfrom the foregoing description. While the device has been shown indetail, it is obvious that this invention is not to be consideredlimited to the exact form disclosed, and that changes may be madetherein within the scope of which is claimed, without departing from thespirit of the invention.

Having thus set forth and described the invention, what is claimed is:

l. A lamp comprising a lamp base, a light filament, and a lamp bulb,said lamp bulb consisting of two concave sections of different radii,the section of larger radius being somewhat flattened and located closerto the lamp filament, the section of smaller radius being substantiallyspherical, a reflecting surface completely covering said section oflarger radius and a reflecting surface on only a portion of thebasalhalf of the small spherical section.

2. A lamp comprising a lamp base, a light filament, and a lamp bulb,said lamb bulb consisting of 'two concave sections of different radii,the section of larger radius being somewhat flattened and located closerto the lamp filament, the section of smaller radius being substantiallyspherical, reflecting surface completely covering said flattened sectionof larger radius, a reflecting surface on only a portion of the basalhalf of the small spherical section and a clear window portion on theremainder to allow light beams to project in a desired direction only.

WARREN G. GRIMES

